This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Over the last few years, many multi-dwelling (“MxU”) establishments, such as hotels, motels, apartments and the like have begun to expand into the business of providing digital data signals, such as digital video or internet services, to their patrons. Besides providing higher quality video than older analog video systems, digital data systems provide the hotel or motel owner the flexibility to supply video-on demand, internet access, and pay-per-view video to each room over one connection. Further, because hotel and motel operators are also usually able to charge residents a premium for digital data services, an increasing number of multi-dwelling establishments are investing in digital data systems. Unfortunately, distribution of digital broadcast signals, such as satellite broadcasts, over wires/networks requires significant amounts of bandwidth. Providing and maintaining this bandwidth can be expensive or prohibitive for the owners of multi-dwelling establishments.
A further problem in the distribution of digital data to a multi-dwelling establishment is the problem of clock jitter. A stable timing clock is vital to the decoding of digital signals because the system clock is used for buffer and color burst control. Without a stable timing clock, the video quality and reliability can be degraded.
Typically, a video broadcast system, such as satellite or cable, will embed a clock signal within the audio/video (“A/V”) data signal by time stamping certain transport packets within the A/V data signal as they are broadcast. Because the delivery of the transport streams is deterministic, the time stamps provide a relative time base between the packets of this type. When one of these packets is received, the receiving system compares its local clock to the time stamp and creates a relative time base. By comparing multiple time stamps within the A/V data signal, the receiving system is able to adjust its local clock until it matches the broadcaster's clock. This type of clock recovery is typically used in digital video broadcast system today. However, because the MxU system converts the A/V data signal into Internet Protocol (“IP”) packets introducing jitter, the conventional method of clock recovery will not work for network set top box systems.